The present disclosure relates to sinus dilation systems and methods. More particularly, relates to inflation devices useful with balloon-based surgical instruments, such as balloon sinus dilation instruments for dilating a portion of a patient's paranasal sinuses in the treatment of sinusitis and other disorders.
The paranasal sinus system is a grouping of four pairs of air-filled cavities that are named for the facial bones in which they are located. The maxillary sinuses surround the nasal cavity, the frontal sinuses are above the eyes, the ethmoid sinuses are between the eyes, and the sphenoid sinuses are within the sphenoid bone at the center of the skull base under the pituitary gland. The paranasal sinuses are lined with respiratory epithelium, are joined to the nasal cavity via small orifices called ostia, and contain secretory tissue that produces a large volume of mucus. This mucus is normally relieved from the sinuses in a specific pattern through the corresponding ostia.
The mucus membrane that lines the paranasal sinuses can become inflamed. This inflammation is known as sinusitis (or rhinosinusitis), and can be caused by various factors such as bacteria, viruses, allergies, anatomical abnormalities, etc. If the mucosa of one of the paranasal sinus passageways becomes inflamed, the passageway can become blocked, trapping mucus. Patients suffering from sinusitis can experience a number of symptoms or complications, such as headache, facial pain, toothache, inner ear problems, etc.
Sinusitis is typically classified as acute (infection lasting 4 or less weeks) or chronic. Many instances of acute sinusitis can be effectively treated with medication (e.g., antibiotics, antihistamines, etc.). Chronic sinusitis may implicate a more invasive treatment option in which the paranasal passageways or affected sinuses are surgically accessed. Conventional sinus surgery entails an incision formed along the side of the nose or through the gums of the upper teeth to provide access to the targeted sinus anatomy. Once accessed, the paranasal sinus passageway in question is surgically enlarged or otherwise altered to facilitate resumption of mucus clearance.
More recently, corrective sinus surgery has been performed endoscopically, minimizing external trauma to the patient. With functional endoscopic sinus surgery (FESS) an endoscope is inserted into the nose. Using visualization through the endoscope, the anatomical and pathological obstructions associated with the sinusitis are removed in order to restore normal mucus clearance. The benefit of FESS (and other intranasal procedures) is the ability to allow for a more targeted approach to the affected sinuses, reducing tissue disruption and minimizing post-operative complications.
An even more recent minimally invasive, intranasal sinus surgery is known as balloon sinus dilation or balloon sinuplasty. Balloon sinus dilation (or simply “sinus dilation”) was initially developed to address the post-operative pain and bleeding associated with FESS. In general terms, conventional sinus dilation is an endoscopic, catheter-based procedure for treating sinusitis using a small, flexible balloon catheter to enlarge or dilate the affected sinus passageway(s). When the balloon is correctly located and inflated, it widens the walls of the sinus passageway, with the goal of restoring normal drainage without damaging the sinus lining.
Prior to performing sinus dilation, the inflator is primed to remove air out of the system. An open end of tubing connected to the inflator is placed in a fluid, such as water, and the fluid is drawn into the inflator. The fluid is expelled from the inflator and the process is repeated one or more times. The balloon is then connected to the open end of the tubing and pressurized with the fluid. The system is then ready for use with another fluid, such as saline, for the sinus dilation. Sometimes, due relocation of the balloon or other reasons, the system is reprimed. Often there is some residue water still remaining in the balloon from the prior priming. This results in additional fluid in the system than potentially realized or desired. The additional fluid in the system can result in overfilling, or over pressurizing, the balloon during sinus dilation.
When performing sinus dilation, the surgeon inserts a sinus guide catheter or cannula through the nostril (or naris) to gain access to the affected sinus ostia (opening) under endoscopic visualization. A guide wire and/or illumination system are then introduced into the targeted sinus via the sinus guide catheter. Once access to the intended targeted location is confirmed by light or fluoroscopy, a flexible catheter, carrying a balloon, is introduced into the sinus cavity over the sinus guide wire, locating the balloon in the blocked ostium. In this regard, the illumination system provides transcutaneous (through the skin) light transmission that the surgeon relies upon when estimating desired balloon placement. Once the desired balloon position has been visually confirmed, the balloon is gradually inflated to dilate the narrowed or blocked ostium. The balloon is then deflated and removed. Next, an irrigation catheter may be advanced over the guide wire to flush out mucus. Finally, the sinus irrigation catheter is removed from the sinus to allow the sinus cavity to drain any mucus. The procedure may be repeated on the other side of the sinus or in a different sinus area (e.g., frontal, sphenoid, or maxillary). Re-priming of the system may be performed prior to beginning the procedure in the next sinus area.
While highly promising, existing sinus dilation systems and methods have several drawbacks. As highlighted by the above, available sinus dilation systems require multiple steps and multiple instruments. While the guide wire can facilitate accessing the targeted sinus site and use of a flexible balloon catheter, surgeons must be trained in the correct use of the guide wire, and the guide wire represents an added cost. Further, the required illumination source and use thereof is time-consuming and relatively expensive. Moreover, a surgeon is required to estimate a location of the targeted ostium only by illumination through the patient's skin. In some instances, the guide wire and/or illumination source may inadvertently be located in a “blind hole”. As a point of reference, regions of the sinus system are pneumatized by various cells in most patients. These cells can build over time, collectively creating an anatomic variation. In some instances, for example, Type II cells can occur at the frontal sinus and can progress to a level that is grossly akin to the frontal sinus ostium. It is estimated that as many as 25% of patients suffering from sinusitis of the frontal sinus have Type II cells. When internally illuminated (and viewed externally), a region of the Type II cell cluster may appear (or “feel”) quite similar to the natural frontal sinus ostium, leading the surgeon to incorrectly assume that the desired ostium has been accessed. When the balloon is subsequently inflated, it may actually occlude the ostium rather than open the ostium.
In addition to the above concerns, the inflation devices utilized with available sinus dilation systems have several drawbacks. As a point of reference, balloon catheters have long been employed for various surgical procedures (e.g., angioplasty, intravascular stent deployment, kyphoplasty, etc.), and inflation devices well-suited for these applications are widely available. Although the anatomical constraints and performance requirements associated with balloon sinus dilation are quite different from other balloon catheter procedures, existing balloon sinus dilation systems default to the already-available inflation devices. Available inflation devices are typically quite large (in order to maintain a sufficient volume of inflation fluid), full featured (e.g., include one or more gauges that display pressure(s) within the device), and complicated to use. For example, mechanical pressure gauges (with dial-type display), electronic pressure gauges (with digital-type display), are included with available balloon catheter inflation devices. While necessary for many balloon catheter procedures, a constant display of current system pressure is of less importance with balloon sinus dilation. These gauges render existing inflation devices highly expensive, especially where the inflation device is intended to be disposable. Further, the gauge(s) may need to be calibrated prior to each use, thereby increasing the time required to complete the procedure. Conversely, other, less-complex inflation devices (e.g., a simple syringe) provide no indication of system pressure, and are void of any warnings or pressure relief when system pressure exceeds particular level(s).
In light of the above, a need exists for improved inflation devices useful with sinus dilation systems and other balloon-based surgical procedures.